The Shovel Claws are a pair of hooked grey metal plates with spiked claws and red cuffs that can be attached over the tops of Knuckles' gloves.
The Shovel Claws are specifically made to enhance Knuckles' digging abilities, providing him with extra sharp and wide claws for penetrating and shifting substances. They can also be used in combat to deal extra harmful hits.
Chaos Emerald Saga
The Shovel Claws originated from Knuckles the Echidna's home world, but were somehow transported to Earth. They were eventually found by Hawk, a human friend of Knuckles, who discovered them inside an old temple on the southern part of a continent. Knuckles eventually took possession of them after he found them inside Hawk's house and used them to dig up a buried Chaos Emerald.
Following the Blue Typhoon's crew into space, Knuckles would put the Shovel Claws to good use several times. One time though, he would use them to attack Chaotix when they drew pictures on him.